Heart Conditions in Children - Cardiomyopathy

What is cardiomyopathy?

Cardiomyopathy occurs due to any disorder of the heart muscle in which the heart loses its ability to pump blood effectively. In some instances, the heart rhythm becomes disturbed and leads to arrhythmias (irregular heartbeats). Cardiomyopathy can be due to a number of causes, including viral infections and certain medications. Often, the exact cause of the muscle disease is never found.

How does cardiomyopathy differ from other heart disorders?

Cardiomyopathy differs from many of the other disorders of the heart in several ways, including the following:

Cardiomyopathy can, and often does, occur in the young.

The condition tends to be progressive and sometimes worsens fairly quickly.

It may be associated with diseases involving other organs, as well as the heart.

Cardiomyopathy is a leading cause for heart transplantation.

Why is cardiomyopathy a concern?

What causes cardiomyopathy?

Viral infections that infect the heart are a major cause of cardiomyopathy. In some instances, cardiomyopathy is a result of another disease or its treatment, such as complex congenital (present at birth) heart disease, nutritional deficiencies, uncontrollable, fast heart rhythms, or certain types of chemotherapy for cancer. Sometimes, cardiomyopathy can be linked to a genetic abnormality. Other times, the cause is unknown. Four types of cardiomyopathy affect both adults and children.

What is dilated cardiomyopathy?

Dilated cardiomyopathy is the most common form of cardiomyopathy. The heart muscle becomes enlarged and stretched (dilated), causing the heart to become weak and pump inefficiently. Other problems that may occur with dilated cardiomyopathy include the following:

Irregular heart rhythms

Risk of blood clots

Congestive heart failure

The dilated left ventricle can affect the leaflets of the mitral valve, which separates the left atrium and the left ventricle, the left-sided chambers of the heart. The valve leaflets become leaky, resulting in mitral regurgitation (or mitral insufficiency) whereby the blood moves backward from the left ventricle to the left atrium, rather moving forward to the body.

Various infections (including viral) which lead to inflammation of the heart muscle (myocarditis) can cause this type of cardiomyopathy.

Contact with toxins or very powerful therapeutic drugs, such as certain types of chemotherapy given to fight cancer, have been known to cause dilated cardiomyopathy. Heredity can also be a factor. Twenty percent of people with dilated cardiomyopathy have a parent or sibling with the disease. In many cases, a specific cause for this type of the disease is never identified.

Because the heart muscle is weak and unable to pump enough blood to meet the body's demands, the body may try to preserve blood flow to essential organs such as the brain and kidneys by reducing blood flow to other areas of the body, such as the skin and muscles.

The following are the most common symptoms of dilated cardiomyopathy. However, each child may experience symptoms differently. Symptoms may include:

Pale or ashen skin color

Cool, sweaty skin

Rapid heart rate

Rapid breathing rate

Shortness of breath

Fatigue

Irritability

Chest pain

Poor appetite

Slow growth

Specific treatment for dilated cardiomyopathy will be determined by your child's health care provider based on:

In some cases, dilated cardiomyopathy due to viral causes improves over time. In other cases, the condition worsens and transplantation of the heart may be considered. Consult your child's health care provider for more information regarding the specific outlook for your child.

What is hypertrophic cardiomyopathy?

In hypertrophic cardiomyopathy, the muscle of the heart becomes thicker than normal, obstructing blood flow to the rest of the body.

The thickened muscle can also affect one of the leaflets of the mitral valve, which separates the left atrium and the left ventricle. The valve leaflet becomes leaky, allowing blood to move backwards from the left ventricle into the left atrium, instead of forward to the rest of the body.

Hypertrophic cardiomyopathy is often hereditary. One-half of children with the disease have a parent or sibling with varying degrees of left ventricular muscle or ventricular wall enlargement, although relatives may or may not have symptoms.

Children with hypertrophic cardiomyopathy may have symptoms that increase with exertion or symptoms may be unpredictable.

The following are the most common symptoms of hypertrophic cardiomyopathy. However, each child may experience symptoms differently. Symptoms may include:

Shortness of breath on exertion

Dizziness

Fainting

Chest pain

Abnormal heart rhythms

Specific treatment for hypertrophic cardiomyopathy will be determined by your child's health care provider based on:

What is restrictive cardiomyopathy?

Restrictive cardiomyopathy, the least common type of cardiomyopathy in the U.S., occurs when the myocardium of the ventricles becomes excessively rigid, and the filling of the ventricles with blood between heart beats is impaired. This condition occurs rarely in children.

Restrictive cardiomyopathy usually results from an underlying condition that affects the rest of the body. However, there are idiopathic (cause unknown) occurrences as well. Restrictive cardiomyopathy does not appear to be inherited, but some of the diseases that lead to the condition are genetically transmitted.

Conditions that may be associated with the development of restrictive cardiomyopathy include, but are not limited to, the following: